The assignee through its developments within the field of protective membranes has provided several generations of the said types of membrane. A first generation of foundation wall membrane is known e.g. from U.S. Pat. No. 3,888,087 (Bergsland), while a second generation foundation wall membrane is described in NO patent 148 041, corresponding to CA 1 186 470 (Bergsland).
These protective membranes of first and second generations have mainly been used as foundation wall membranes applied as a cladding to the outer foundation wall of a house before back fill is placed next to it. Such foundation wall membranes are preferably manufactured with knobs which do not readily yield due to the outside forces from e.g. backfilling.
Recently it has also become usual for such foundation wall membranes to be used as a vapour barrier for slab-on-ground, and NO patent application 894899, corresponding to U.S. Pat. No. 5,107,642 (Mogstad) describes the use of such membranes for the protection of dwellings from penetration of fluids, especially unpleasant or noxious gases. Similar membranes are also described in assignee's U.S. Pat. No. 5,044,821 (Johnsen).
Available from the assignee are today systems based on the above mentioned protective membranes, particularly for protection from dampness of floors both with and without mechanical ventilation, and especially Norwegian patent application 89 4899 (U.S. Pat. No. 5,107,642) describes a so-called radon solution which preferably uses a protective membrane or a foundation wall membrane with knobs, manufactured in accordance with NO patent 148 041 (CA 1,186,470). (U.S. Pat. No. 3,888,087).
In connection with rehabilitation of basements and in connection with houses with no basements, built on a so-called slab-on-ground, there is a growing demand for a protective membrane on the concrete foundation which may provide the necessary protection, while at the same time constitute part of the assignee's system for mechanical ventilation. Also in connection with the construction of blocks of flats with floors at different levels, it is perhaps often relevant to have such protective membranes next to the untreated floor, especially if it has been levelled with a liquid smoother which emits noxious and/or unpleasant vapours.
In connection with those types of floor, both with regard to basement floors and floors at different levels in blocks of flats, there is, however, a user demand for a finished floor of good ergonomic properties, that is to say that the floor must be comfortable to walk on, and especially where floor dividers in apartment blocks are concerned, there is an increasing demand for particular sound insulating properties in such multi-purpose floors which may be made with or without mechanical ventilation.